scholarly journals The availability of Cd, Pb and Zn and their relationships with soil pH and microbial biomass in soils amended by natural clinoptilolite

2011 ◽  
Vol 51 (No. 1) ◽  
pp. 26-33 ◽  
Author(s):  
G. Mühlbachová ◽  
T. Šimon ◽  
M. Pechová
Keyword(s):  
Heavy Metal ◽  
Microbial Biomass ◽  
Contaminated Soils ◽  
Metal Availability ◽  
Maximum Increase ◽  
Glucose Addition ◽  
Soil Microbial ◽  
Significant Relationships ◽  
Metal Contents ◽  
Natural Clinoptilolite

The relationships among soil microbial biomass, pH and available of heavy metal fractions were evaluated in longterm contaminated soils during an incubation experiment with the amendment of zeolite (natural clinoptilolite) and the subsequent addition of glucose. The values of pH after the addition of glucose decreased during the first day of incubation approximately at about one unit and corresponded with the maximum increase of microbial biomass. The available heavy metal contents extracted by H<sub>2</sub>O, 1 mol/l NH<sub>4</sub>NO<sub>3</sub> and 0.005 mol/l DTPA increased during the first two days of incubation. Only a few significant relationships were found between the available metal contents and pH or microbial biomass. This fact could be ascribed to the different dynamics of the microbial biomass, pH and metal availability after glucose addition, when the highest metal contents during the incubation were usually reached one day later in respect to the greatest changes of pH and microbial activity. In comparison to soils without zeolite addition, the variants with natural clinoptilolite showed lower heavy metal contents in all used extractants with the exception of Cd which in H<sub>2</sub>O extracts tended to increase.

scholarly journals The availability of DTPA extracted heavy metals during laboratory incubation of contaminated soils with glucose amendments

2011 ◽  
Vol 48 (No. 12) ◽  
pp. 536-542
Author(s):  
G. Mühlbachová
Keyword(s):  
Heavy Metal ◽  
Contaminated Soils ◽  
Metal Availability ◽  
Percentage Increase ◽  
Lead Smelter ◽  
Soil Microbial ◽  
Laboratory Incubation ◽  
Microbial Characteristics ◽  
Metal Contents ◽  
The Comparative Study

The laboratory incubation with glucose treatment was carried out in order to estimate the possible effects of increased microbial activity on heavy metal availability. The soils from vicinity of a&nbsp;lead smelter operating for more than 200 years were used for the experiment. The DTPA-extractable heavy metal contents increased after glucose addition and mostly reached the highest values the second day of the incubation. The comparative study, where the chloroform fumigation was used prior to the incubation in order to decrease the microbial activities, showed especially from second day of incubation significantly lower DTPA-extractable metal contents compared to non-fumigated treatments. The interactions among the maximum possible availability of DTPA-extractable heavy metal fractions and native soil microbial characteristics were studied in differently contaminated arable and grassland soils. Irrespective of different heavy metal contents in soils, significant correlations were found among the maximum percentage increase of DTPA-extractable Pb and Cd and the ratio Bc/TOC and metabolic quotient (qCO<sub>2</sub>) which may be a&nbsp;result of the important role of organic matter and microbial characteristics in soils on the heavy metal availability.

Soil microbial biomass as a marker of heavy metal contamination and bioavailability

1997 ◽  
pp. 449-457 ◽  
Author(s):  
L. Leita ◽  
G. Muhlbachova ◽  
C. Mondini ◽  
L. Marchiol ◽  
M. de Nobili
Keyword(s):  
Heavy Metal ◽  
Microbial Biomass ◽  
Metal Contamination ◽  
Soil Microbial Biomass ◽  
Heavy Metal Contamination ◽  
Soil Microbial

scholarly journals Heavy metal accumulation in tomato and cabbage grown in some industrially contaminated soils of Bangladesh

2019 ◽  
Vol 17 (3) ◽  
pp. 288-294
Author(s):  
Md Akhter Hossain Chowdhury ◽  
Tanzin Chowdhury ◽  
Md Arifur Rahman
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Contaminated Soils ◽  
Metal Accumulation ◽  
Living System ◽  
Heavy Metal Accumulation ◽  
World Health ◽  
Agricultural Field ◽  
Allowable Limit ◽  
Metal Contents

Heavy metal accumulation in environmental compartments is a potential risk to the living system because of their uptake by plants and subsequent introduction into the food chain. A study was carried out to investigate the heavy metal contents in industrially contaminated soils collected from six different locations of Dhaka and Mymensingh districts and their effects on two important vegetables namely tomato and cabbage. Pot experiment was conducted using contaminated soils at the net house of Bangladesh Institute of Nuclear Agriculture (BINA), Mymensingh following completely randomized design (CRD) with three replicates. The higher level of heavy metal contents was found in the soil samples of Hajaribag and Dhaka Export Processing Zone (DEPZ). The highest Ni, Cd, Cr, Cu and Fe contents were 59.45, 18.79, 67.57, 40.81 and 1619.61 µg g−1 which were much above the recommended level except Cu contents. The highest yield of vegetables was obtained grown in Maskanda soil of Mymensingh district and the lowest from DEPZ soil of Dhaka. The highest Ni, Cr and Fe contents were 8.91, 7.22, 419.65 µg g−1, respectively in tomato fruits grown in the soil of Hajaribag whereas the highest Cu content (3.38 µg g−1) was obtained from Seedstore soil, Mymensingh and highest Cd content (2.88 µg g−1) was from Mitford ghat soil, Dhaka. In cabbage, the highest Ni (17.52 µg g−1) and Fe (411.25 µg g−1) contents were found in the soils of DEPZ whereas the highest Cr (9.17 µg g−1), Cd (3.52 µg g−1) and Cu (8.51 µg g−1) were obtained in the plants grown in the soils of Hajaribag, Mitford ghat and Maskanda, respectively. Concentrations of all the tested heavy metals except Cu in both vegetables were above the maximum allowable limit prescribed by the World Health Organization. Among the metals, the accumulation of Ni was found as higher amount (0.39 and 0.71 for tomato and cabbage, respectively) based on plant concentration factor or transfer factor. The results showed a positive correlation between concentration of the metals present in soils and in vegetables and the highest correlation was found with Cr in tomato and Fe in cabbage. However, both the soils and grown vegetables were consistently observed to pose a risk to human health. So, it can be recommended that government should take necessary action so that heavy metals used in the industries cannot come into the nearby agricultural field to ensure food safety as well as food security. J Bangladesh Agril Univ 17(3): 288–294, 2019

Heavy metal availability to plants in soils irrigated with wastewater from Mexico City

1995 ◽  
Vol 32 (12) ◽  
pp. 29-34 ◽  
Author(s):  
Christina Siebe
Keyword(s):  
Heavy Metal ◽  
Mexico City ◽  
Metal Uptake ◽  
Metal Availability ◽  
Tolerance Limits ◽  
Aqua Regia ◽  
Untreated Wastewater ◽  
Metal Contents ◽  
Irrigation Time ◽  
The Relationship

The relationship between three different heavy metal fractions in soils irrigated for long periods of time with untreated wastewater from Mexico City and the metal uptake by alfalfa (Medicago sativa) was studied in order to evaluate actual accumulation levels in soils, as well as to establish which extracting solution characterizes most precisely the availability of selected heavy metals to plants. Cd, Pb, Cu and Zn were analyzed in aqua regia, 1 M NH4NO3 and water extracts from 50 soil samples and correlated with total contents in alfalfa tissue collected at the same sites. Heavy metal contents of the 3 fractions increase significantly with irrigation time, but European tolerance limits are slightly exceeded only for Cd at some sites. Plant uptake of Cd and Pb also increases the longer the soils have been irrigated and correlates best with aqua regia extracts from soils.

scholarly journals Biochar alleviates metal toxicity and improves microbial community functions in a soil co-contaminated with cadmium and lead

Biochar ◽  
2021 ◽  
Author(s):  
Nahid Azadi ◽  
Fayez Raiesi
Keyword(s):  
Heavy Metals ◽  
Low Temperature ◽  
Organic Carbon ◽  
Enzymatic Activity ◽  
Microbial Activity ◽  
Contaminated Soils ◽  
Metal Availability ◽  
Soil Microbial ◽  
Labile C ◽  
Cadmium And Lead

AbstractSoil amendment with biochar alleviates the toxic effects of heavy metals on microbial functions in single-metal contaminated soils. Yet, it is unclear how biochar application would improve microbial activity and enzymatic activity in soils co-polluted with toxic metals. The present research aimed at determining the response of microbial and biochemical attributes to addition of sugarcane bagasse biochar (SCB) in cadmium (Cd)-lead (Pb) co-contaminated soils. SCBs (400 and 600 °C) decreased the available concentrations of Cd and Pb, increased organic carbon (OC) and dissolved organic carbon (DOC) contents in soil. The decrease of metal availability was greater with 600 °C SCB than with 400 °C SCB, and metal immobilization was greater for Cd (16%) than for Pb (12%) in co-spiked soils amended with low-temperature SCB. Biochar application improved microbial activity and biomass, and enzymatic activity in the soils co-spiked with metals, but these positive impacts of SCB were less pronounced in the co-spiked soils than in the single-spiked soils. SCB decreased the adverse impacts of heavy metals on soil properties largely through the enhanced labile C for microbial assimilation and partly through the immobilization of metals. Redundancy analysis further confirmed that soil OC was overwhelmingly the dominant driver of changes in the properties and quality of contaminated soils amended with SCB. The promotion of soil microbial quality by the low-temperature SCB was greater than by high-temperature SCB, due to its higher labile C fraction. Our findings showed that SCB at lower temperatures could be applied to metal co-polluted soils to mitigate the combined effects of metal stresses on microbial and biochemical functions.

Stabilization of labile carbon in soil microbial biomass and necromass – A question of nitrogen deficiency?

2020 ◽  
Author(s):  
Nele Meyer ◽  
Outi-Maaria Sietiö ◽  
Sylwia Adamczyk ◽  
Christina Biasi ◽  
Per Ambus ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Soil Microbial Biomass ◽  
Bare Soil ◽  
Glucose Addition ◽  
Soil Microbial ◽  
Labile C ◽  
Long Time ◽  
N Demand ◽  
Water Extractable ◽  
Microbial N

&lt;p&gt;It has been assumed for a long time that stable soil organic carbon (SOC) results from selective preservation of plant residues. Yet, a new paradigm points to a more active role of microorganisms in building SOC storage. In this context, even labile C, such as sugars, may persist in soil for a long time due to their incorporation into microbial biomass and ultimately necromass. The latter is considered as a relatively stable pool. However, little is known about the cycling of labile C through the microbial biomass and the turnover time of its residues. Unraveling the mechanisms and regulating factors would be critical for understanding SOC stabilization in soil.&lt;/p&gt;&lt;p&gt;We assume that the fate of labile C is mainly driven by microbial nitrogen (N) demand and supply. Specifically, we hypothesize that (1) high N demand forces microbes to decompose N-rich substances (&amp;#8220;microbial N mining&amp;#8221;), such as amino sugars, leading to a rapid turnover of microbial necromass, and that (2) labile C is stabilized in microbial necromass when N demand is met.&lt;/p&gt;&lt;p&gt;To investigate these hypotheses, we set up a greenhouse pot experiment including four treatments: (1) bare soil, (2) bare soil+N, (3) tree, and (4) tree+N. The soil is a sandy and nutrient poor forest soil from southern Finland. Trees are 1 m high pines (Pinus Sylvestris), which are supposed to induce microbial N deficiency by exuding easily degradable C compounds and by competing with microbes for mineral N. In order to follow to fate of labile C, we added trace amounts of &lt;sup&gt;13&lt;/sup&gt;C labeled glucose to the soil (4 replicates per treatment). As a control to account for background variations in &lt;sup&gt;13&lt;/sup&gt;C, we added &lt;sup&gt;12&lt;/sup&gt;C glucose to another set of pots (4 replicates per treatment). Up to now, we sampled the soil 1 day, 3 days, 8 days, 1 month, 3 months, 6 months, 9 months, and 1 year after glucose addition. Measurements of the &lt;sup&gt;13&lt;/sup&gt;C recovery in soil, microbial biomass, water extractable C, PLFA, amino sugars, and DNA are in progress.&lt;/p&gt;&lt;p&gt;First results indicate that the largest loss of &lt;sup&gt;13&lt;/sup&gt;C tracer occurred in the unfertilized tree treatment, i.e., where N demand was high but N supply was low. Here, only 22% of the &lt;sup&gt;13&lt;/sup&gt;C glucose remained after 3 month, whereas 40% remained in the fertilized tree treatment. Only small proportions of the recovered &lt;sup&gt;13&lt;/sup&gt;C were present in the pool of water extractable C (&lt;1%) and in living microbial biomass (8&amp;#177;3%, 3 days after glucose addition). As protection by clay minerals and aggregates is likely not a relevant process in this sandy soil, we suspect the remaining &lt;sup&gt;13&lt;/sup&gt;C to be stabilized in microbial residues, but depending on N demand. We assume that microbial necromass accounts for a considerable proportion to total SOC storage, especially under conditions of adequate nitrogen supply.&lt;/p&gt;

scholarly journals Microbial biomass dynamics after addition of EDTA into heavy metal contaminated soils

2009 ◽  
Vol 55 (No. 12) ◽  
pp. 544-550 ◽  
Author(s):  
G. Mühlbachová
Keyword(s):  
Heavy Metal ◽  
Microbial Biomass ◽  
Contaminated Soils ◽  
Soil Microorganisms ◽  
Organic Substrate ◽  
Microbial Biomass C ◽  
Microbial Activities ◽  
Arable Soils ◽  
Microbial Properties ◽  
Biomass Dynamics

An incubation experiment with addition of EDTA and alfalfa into soils contaminated with heavy metal over 200 years was carried out in order to evaluate the EDTA effects on microbial properties. Alfalfa was added to soils together with EDTA to examine its abilities to improve microbial activities affected by EDTA. The obtained results showed that the addition of EDTA led to a significant decrease of microbial biomass C during the first 24 days of incubation. At the end of the experiment the microbial biomass C significantly increased quite close to the original level. The EDTA amendment caused, probably due to the toxic effects, a significant increase in respiratory activities and of the metabolic quotient <i>q</i>CO<sub>2</sub>. An addition of alfalfa significantly improved the microbial biomass C contents in arable soils treated together with EDTA. Both, respiratory activities and <i>q</i>CO<sub>2</sub> significantly increased after the soil treatment with EDTA together with alfalfa. EDTA alone decreased the microbial biomass, alfalfa alone as organic substrate was mineralised and utilised by soil microorganisms for their metabolism.

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